A Provocative Rant About Machine Espresso > 자유게시판

How Does Machine Espresso Work?

Machine espresso employs precise pressure and amazing filter technology to make the delicious coffee we enjoy. How does it work exactly?

Espresso is produced by pushing hot water under pressure through finely-ground coffee. The process is similar to making drip coffee but the major difference is in the pressure.

The Head of the Group

The group head is the portafilter that is inserted when you are making espresso. It is responsible for dispersing the water into the portafilter, and controlling the pressure of the extraction. There are a variety of group heads each with its own advantages and drawbacks. Some are specifically designed for stability of temperature while others are built to handle pre-infusion. Others are made to control the lever. Some have a combination, such as the E61. This is a very popular choice for baristas due to the fact that it has multiple benefits in a single package.

As you can see in the above photo the group head has a number of notches. It is possible to place your portafilter in these notches and then turn the head around to secure it. There is also a gasket of rubber which is located inside the notches and helps to create a seal when you insert your portafilter into the machine. The notches allow for precise placement of your portafilter. This is crucial for an even extraction.

In addition to allowing you to easily connect your portafilter, the group head is also responsible for maintaining a consistent temperature. It does this by circulating hot water through the brew basket, and around the portafilter, making sure that it's always at the right temperature to extract. This is vital, because just a few degrees could make the difference between a good and great espresso.

The Pump

The motorized pumps used in cafe espresso machine machines rotary provide nine atmospheric bar pressure required to extract espresso. This differs from manual piston machines that use a lever. The pressure is built by pumping water through a heat-exchanger and then through the ground coffee.

Pumps are generally less expensive and last for longer than piston-driven machines. However, both kinds of machines can deteriorate because of excessive use and insufficient cleaning. They also add mechanical complexity and can lead to the cost of even the most basic models.

Some espresso machines employ steam pressure instead of a pump in order to brew cheap espresso machine. This can cause over-extraction because the boiler that produces steam also warms the water to boil. These machines also have to constantly rebuild their pressure between cups. This requires energy and time.

Many espresso machines utilize an rotary or vibrating pump, with a vibrating model using a rotating disc to create the pressure, and an rotary model that pushes hot water through the grounds under high speed. Both models are capable of producing excellent espresso, but the rotary models are quieter and more durable than vibration pumps.

The Boiler

The boiler is the element that heats the water to the ideal temperature for extraction. The resultant steam then reaches the portafilter which holds the ground espresso and gets funnelled down into the cup. During this process the steam causes enough pressure to push the coffee grounds through. This results in a crema on the top of the espresso capsule machine. This is the hallmark of a good espresso.

There are three kinds of espresso coffee makers machines, each having different pumps and the temperature of the brew. There are a variety of ways to control the brew as well as the size of cup that can be produced by the machine.

The earliest espresso machines were steam-based. The earliest espresso machines were steam-type machines. This led to the coffee tasting burnt and bitter. The modern espresso machine was developed by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

The most commonly used espresso maker is a semi-automatic device with an electric espresso maker pump. These are what people imagine when they imagine an espresso machine. If you have a semi-automatic machine you have to grind the beans and then tamp them by hand, but the pump regulates the flow of water and pressure. This is a fantastic combination of human control and mechanised accuracy.

The Filter

Typically, espresso machines employ a filter to separate out the grounds of coffee as they move through the hot water. The filter is also an essential part of the temperature control system, as it prevents the machine from overheating.

A filter also helps with flavor because it allows for a longer flowering phase. This helps the beans to let their nuances out and provides the chance for better extraction.

However it is crucial to keep in mind that even a high-quality filter could result in a bad cup of coffee, since the quality of the beans and extraction is still important.

It's here that the magic occurs. This is the reason why espresso tastes so good. The grouphead, also referred to as the brew head, is the place where the portafilter (the thing you put the ground coffee into) sits when you're making espresso.

Steam-driven professional espresso machine machines use hot water that is heated inside an airtight container to make steam. The steam then pushes hot water through grounds of the coffee under pressure. These machines are cheaper and are easier for the user to maintain than pumps-driven models. However, they are limited in their ability to provide the perfect brewing conditions since they are only operating at 1-1.5 bars of pressure, while the perfect shot requires 9-10 bar.

In recent years, espresso machines powered by compressed air-pump are becoming increasingly popular. They utilize an air compressor to force hot water through the grounds and are much more portable than electric steam-driven machines.